HE staining of myocardial tissue showed that a large number of inflammatory cells infiltrated the WT ischemia group myocardium compared to the WT sham group, but the number of inflammatory cells decreased notably when PCSK9 expression was knocked down (13.6 ± 1.39% vs. 7.50 ± 0.81%, P < 0.05) (Figure 2(g)). The gene discussed is PCSK9; the disease is ischemia.